Browsing by Author "Davidson, Rachel A."

Now showing 1 - 5 of 5
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    Can visits to certain businesses help predict evacuation decisions in real time?
    (Natural Hazards, 2025-01-06) Anyidoho, Prosper K.; Davidson, Rachel A.; Nozick, Linda K.; Trivedi, Jennifer; DeYoung, Sarah E.; Wachtendorf, Tricia
    This study aims to help understand and predict evacuation behavior by examining the relationship between evacuation decisions and visits to certain businesses using smartphone location and point of interest (POI) data collected across three hurricanes—Dorian (2019), Ida (2021), and Ian (2022)—for residents in voluntary and mandatory evacuation zones. Results from these data suggest residents visit POIs as part of preparatory activities before a hurricane impacts land. Statistical tests suggest that POI visits can be used as precursor signals for predicting evacuations in real time. Specifically, people are more likely to evacuate if they visit a gas station and are more likely to stay if they visit a grocery store, hardware store, pet store, or a pharmacy prior to landfall. Additionally, they are even less likely to leave if they visit multiple places of interest. These results provide a foundation for using smartphone location data in real time to improve predictions of behavior as a hurricane approaches.
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    Managing disaster risk associated with critical infrastructure systems: a system-level conceptual framework for research and policy guidance
    (Civil Engineering and Environmental Systems, 2022-04-25) Davidson, Rachel A.; Kendra, James; Ewing, Bradley; Nozick, Linda K.; Starbird, Kate; Cox, Zachary; Leon-Corwin, Maggie
    This paper presents a new conceptual framework of the disaster risk of critical infrastructure systems in terms of societal impacts. Much research on infrastructure reliability focuses on specific issues related to the technical system or human coping. Focusing on the end goal of infrastructure services – societal functioning – this framework offers a new way to understand how those more focused research areas connect and the current thinking in each. Following an overview of the framework, each component is discussed in turn, including the initial buildout of physical systems; event occurrence; service interruptions; service provider response; user adaptations to preserve or create needed services; and the ending deficit in societal function. Possible uses of the framework include catalysing and guiding a systematic research agenda that could ultimately lead to a computational framework and stimulating discussion on resilience within utility and emergency management organisations and the larger community.
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    Regional county-level housing inventory predictions and the effects on hurricane risk
    (Natural Hazards and Earth System Sciences, 2022-03-30) Williams, Caroline J.; Davidson, Rachel A.; Nozick, Linda K.; Trainor, Joseph E.; Millea, Meghan; Kruse, Jamie L.
    Regional hurricane risk is often assessed assuming a static housing inventory, yet a region's housing inventory changes continually. Failing to include changes in the built environment in hurricane risk modeling can substantially underestimate expected losses. This study uses publicly available data and a long short-term memory (LSTM) neural network model to forecast the annual number of housing units for each of 1000 individual counties in the southeastern United States over the next 20 years. When evaluated using testing data, the estimated number of housing units was almost always (97.3 % of the time), no more than 1 percentage point different than the observed number, predictive errors that are acceptable for most practical purposes. Comparisons suggest the LSTM outperforms the autoregressive integrated moving average (ARIMA) and simpler linear trend models. The housing unit projections can help facilitate a quantification of changes in future expected losses and other impacts caused by hurricanes. For example, this study finds that if a hurricane with characteristics similar to Hurricane Harvey were to impact southeastern Texas in 20 years, the residential property and flood losses would be nearly USD 4 billion (38 %) greater due to the expected increase of 1.3 million new housing units (41 %) in the region.
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    REWET: A Tool to Model System Functioning and Restoration of Damaged Water Supply Systems
    (Journal of Infrastructure Systems, 2024-09-14) Naeimi, Sina; Davidson, Rachel A.
    The process of restoring water supply after service is interrupted is critical for determining the durations and spatial distribution of outages and thus the impacts that households, businesses, and others ultimately experience. Nevertheless, the restoration period is difficult to predict because it involves complex, dynamic interactions among the system hydraulics, operator restoration actions, and consumer adaptations to service interruptions. In this paper, we introduce a new computer model called Restoration of Water after an Event Tool (REWET) that (1) allows detailed representations of both the hydraulic operations of the system and the restoration process, (2) is flexible enough to apply to any system or disruptive event, enable varying levels of complexity, and allow deterministic or probabilistic analysis, and (3) is available as free, easy-to-use, open-source code. It uses pressure-demand driven hydraulic analysis and allows detailed discrete event simulation representation of the restoration process. We present case study applications of REWET for the Los Angeles water system and for a small, simple network to illustrate the tool’s functionality, flexibility, and key features.
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    San Bruno California, September 9, 2010 Gas Pipeline Explosion and Fire
    (Disaster Research Center, 2012) Davidson, Rachel A.; Kendra, James; Li, Sizheng; Long, Laurie C.; McEntire, David A.; Scawthorn, Charles; Kelly, Joshua
    On September 9, 2010 a buried high pressure 30-inch steel natural gas pipeline exploded in a residential neighborhood in the City of San Bruno, California, a suburb of San Francisco. The explosion and ensuing fire killed 8 and injured 58, and destroyed 38 and damaged 70 homes. During the first 50 hours following the incident, over 500 firefighters and 90 apparatus responded, involving 42 fire agencies. The total cost of the disaster is estimated to be approximately $1.6 billion. Local and regional jurisdictions have been engaged in extensive and sophisticated recovery and reconstruction operations, which continue as of this writing. This report, funded by the National Science Foundation under a RAPID grant, is based on site visits, interviews, and secondary data collection, and addresses emergency response and recovery from two perspectivesengineering and social science. Causes of the explosion were examined by the National Transportation Safety Board and are not considered in detail. Semi-structured interviews were conducted with public officials of the principal fire and emergency services and with representatives of non-profit organizations active in the area. Team members made several site visits from immediately after the event in September 2010 to February 2011. Key findings and research issues identified include the following. First, there are difficult theoretical and practical questions about the ability of infrastructure organizations to maintain their attention on their own operations over long periods, resulting in degrading safety and reliability. Second, there are similarities between this isolated event and what may occur in a major earthquake in the San Francisco Bay Area. This event was well responded to; in a major earthquake, similar resources are likely to be unavailable, potentially leading to significant secondary (i.e., fire following earthquake) losses. Third, three current engineering risk methods for estimation of safety zones around gas transmission lines were examined and generally validated vis-à-vis data from the incident. Fourth, detailed timelines and actions by emergency responders and recovery officials are recorded, providing a basis for future research on issues of expedient or spontaneous planning in emergencies. Fifth, a georeferenced database of almost 300 photographs of damage resulting from the incident is appended to the report, for use by researchers in examining fire spread and other issues.